1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Copyright (C) 2001 PPC64 Team, IBM Corp 4 * 5 * This struct defines the way the registers are stored on the 6 * kernel stack during a system call or other kernel entry. 7 * 8 * this should only contain volatile regs 9 * since we can keep non-volatile in the thread_struct 10 * should set this up when only volatiles are saved 11 * by intr code. 12 * 13 * Since this is going on the stack, *CARE MUST BE TAKEN* to insure 14 * that the overall structure is a multiple of 16 bytes in length. 15 * 16 * Note that the offsets of the fields in this struct correspond with 17 * the PT_* values below. This simplifies arch/powerpc/kernel/ptrace.c. 18 */ 19 #ifndef _ASM_POWERPC_PTRACE_H 20 #define _ASM_POWERPC_PTRACE_H 21 22 #include <linux/err.h> 23 #include <uapi/asm/ptrace.h> 24 #include <asm/asm-const.h> 25 26 #ifndef __ASSEMBLY__ 27 struct pt_regs 28 { 29 union { 30 struct user_pt_regs user_regs; 31 struct { 32 unsigned long gpr[32]; 33 unsigned long nip; 34 unsigned long msr; 35 unsigned long orig_gpr3; 36 unsigned long ctr; 37 unsigned long link; 38 unsigned long xer; 39 unsigned long ccr; 40 #ifdef CONFIG_PPC64 41 unsigned long softe; 42 #else 43 unsigned long mq; 44 #endif 45 unsigned long trap; 46 unsigned long dar; 47 unsigned long dsisr; 48 unsigned long result; 49 }; 50 }; 51 #if defined(CONFIG_PPC64) || defined(CONFIG_PPC_KUAP) 52 union { 53 struct { 54 #ifdef CONFIG_PPC64 55 unsigned long ppr; 56 #endif 57 union { 58 #ifdef CONFIG_PPC_KUAP 59 unsigned long kuap; 60 #endif 61 #ifdef CONFIG_PPC_PKEY 62 unsigned long amr; 63 #endif 64 }; 65 #ifdef CONFIG_PPC_PKEY 66 unsigned long iamr; 67 #endif 68 }; 69 unsigned long __pad[4]; /* Maintain 16 byte interrupt stack alignment */ 70 }; 71 #endif 72 }; 73 #endif 74 75 76 #define STACK_FRAME_WITH_PT_REGS (STACK_FRAME_OVERHEAD + sizeof(struct pt_regs)) 77 78 #ifdef __powerpc64__ 79 80 /* 81 * Size of redzone that userspace is allowed to use below the stack 82 * pointer. This is 288 in the 64-bit big-endian ELF ABI, and 512 in 83 * the new ELFv2 little-endian ABI, so we allow the larger amount. 84 * 85 * For kernel code we allow a 288-byte redzone, in order to conserve 86 * kernel stack space; gcc currently only uses 288 bytes, and will 87 * hopefully allow explicit control of the redzone size in future. 88 */ 89 #define USER_REDZONE_SIZE 512 90 #define KERNEL_REDZONE_SIZE 288 91 92 #define STACK_FRAME_OVERHEAD 112 /* size of minimum stack frame */ 93 #define STACK_FRAME_LR_SAVE 2 /* Location of LR in stack frame */ 94 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x7265677368657265) 95 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + \ 96 STACK_FRAME_OVERHEAD + KERNEL_REDZONE_SIZE) 97 #define STACK_FRAME_MARKER 12 98 99 #ifdef PPC64_ELF_ABI_v2 100 #define STACK_FRAME_MIN_SIZE 32 101 #else 102 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 103 #endif 104 105 /* Size of dummy stack frame allocated when calling signal handler. */ 106 #define __SIGNAL_FRAMESIZE 128 107 #define __SIGNAL_FRAMESIZE32 64 108 109 #else /* __powerpc64__ */ 110 111 #define USER_REDZONE_SIZE 0 112 #define KERNEL_REDZONE_SIZE 0 113 #define STACK_FRAME_OVERHEAD 16 /* size of minimum stack frame */ 114 #define STACK_FRAME_LR_SAVE 1 /* Location of LR in stack frame */ 115 #define STACK_FRAME_REGS_MARKER ASM_CONST(0x72656773) 116 #define STACK_INT_FRAME_SIZE (sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD) 117 #define STACK_FRAME_MARKER 2 118 #define STACK_FRAME_MIN_SIZE STACK_FRAME_OVERHEAD 119 120 /* Size of stack frame allocated when calling signal handler. */ 121 #define __SIGNAL_FRAMESIZE 64 122 123 #endif /* __powerpc64__ */ 124 125 #ifndef __ASSEMBLY__ 126 127 static inline unsigned long instruction_pointer(struct pt_regs *regs) 128 { 129 return regs->nip; 130 } 131 132 static inline void instruction_pointer_set(struct pt_regs *regs, 133 unsigned long val) 134 { 135 regs->nip = val; 136 } 137 138 static inline unsigned long user_stack_pointer(struct pt_regs *regs) 139 { 140 return regs->gpr[1]; 141 } 142 143 static inline unsigned long frame_pointer(struct pt_regs *regs) 144 { 145 return 0; 146 } 147 148 #ifdef CONFIG_SMP 149 extern unsigned long profile_pc(struct pt_regs *regs); 150 #else 151 #define profile_pc(regs) instruction_pointer(regs) 152 #endif 153 154 long do_syscall_trace_enter(struct pt_regs *regs); 155 void do_syscall_trace_leave(struct pt_regs *regs); 156 157 #ifdef __powerpc64__ 158 #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) 159 #else 160 #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) 161 #endif 162 163 #define force_successful_syscall_return() \ 164 do { \ 165 set_thread_flag(TIF_NOERROR); \ 166 } while(0) 167 168 #define current_pt_regs() \ 169 ((struct pt_regs *)((unsigned long)task_stack_page(current) + THREAD_SIZE) - 1) 170 171 /* 172 * The 4 low bits (0xf) are available as flags to overload the trap word, 173 * because interrupt vectors have minimum alignment of 0x10. TRAP_FLAGS_MASK 174 * must cover the bits used as flags, including bit 0 which is used as the 175 * "norestart" bit. 176 */ 177 #ifdef __powerpc64__ 178 #define TRAP_FLAGS_MASK 0x1 179 #else 180 /* 181 * On 4xx we use bit 1 in the trap word to indicate whether the exception 182 * is a critical exception (1 means it is). 183 */ 184 #define TRAP_FLAGS_MASK 0xf 185 #define IS_CRITICAL_EXC(regs) (((regs)->trap & 2) != 0) 186 #define IS_MCHECK_EXC(regs) (((regs)->trap & 4) != 0) 187 #define IS_DEBUG_EXC(regs) (((regs)->trap & 8) != 0) 188 #endif /* __powerpc64__ */ 189 #define TRAP(regs) ((regs)->trap & ~TRAP_FLAGS_MASK) 190 191 static __always_inline void set_trap(struct pt_regs *regs, unsigned long val) 192 { 193 regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK); 194 } 195 196 static inline bool trap_is_scv(struct pt_regs *regs) 197 { 198 return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000); 199 } 200 201 static inline bool trap_is_unsupported_scv(struct pt_regs *regs) 202 { 203 return IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x7ff0; 204 } 205 206 static inline bool trap_is_syscall(struct pt_regs *regs) 207 { 208 return (trap_is_scv(regs) || TRAP(regs) == 0xc00); 209 } 210 211 static inline bool trap_norestart(struct pt_regs *regs) 212 { 213 return regs->trap & 0x1; 214 } 215 216 static __always_inline void set_trap_norestart(struct pt_regs *regs) 217 { 218 regs->trap |= 0x1; 219 } 220 221 #define kernel_stack_pointer(regs) ((regs)->gpr[1]) 222 static inline int is_syscall_success(struct pt_regs *regs) 223 { 224 if (trap_is_scv(regs)) 225 return !IS_ERR_VALUE((unsigned long)regs->gpr[3]); 226 else 227 return !(regs->ccr & 0x10000000); 228 } 229 230 static inline long regs_return_value(struct pt_regs *regs) 231 { 232 if (trap_is_scv(regs)) 233 return regs->gpr[3]; 234 235 if (is_syscall_success(regs)) 236 return regs->gpr[3]; 237 else 238 return -regs->gpr[3]; 239 } 240 241 static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) 242 { 243 regs->gpr[3] = rc; 244 } 245 246 #define arch_has_single_step() (1) 247 #define arch_has_block_step() (true) 248 #define ARCH_HAS_USER_SINGLE_STEP_REPORT 249 250 /* 251 * kprobe-based event tracer support 252 */ 253 254 #include <linux/stddef.h> 255 #include <linux/thread_info.h> 256 extern int regs_query_register_offset(const char *name); 257 extern const char *regs_query_register_name(unsigned int offset); 258 #define MAX_REG_OFFSET (offsetof(struct pt_regs, dsisr)) 259 260 /** 261 * regs_get_register() - get register value from its offset 262 * @regs: pt_regs from which register value is gotten 263 * @offset: offset number of the register. 264 * 265 * regs_get_register returns the value of a register whose offset from @regs. 266 * The @offset is the offset of the register in struct pt_regs. 267 * If @offset is bigger than MAX_REG_OFFSET, this returns 0. 268 */ 269 static inline unsigned long regs_get_register(struct pt_regs *regs, 270 unsigned int offset) 271 { 272 if (unlikely(offset > MAX_REG_OFFSET)) 273 return 0; 274 return *(unsigned long *)((unsigned long)regs + offset); 275 } 276 277 /** 278 * regs_within_kernel_stack() - check the address in the stack 279 * @regs: pt_regs which contains kernel stack pointer. 280 * @addr: address which is checked. 281 * 282 * regs_within_kernel_stack() checks @addr is within the kernel stack page(s). 283 * If @addr is within the kernel stack, it returns true. If not, returns false. 284 */ 285 286 static inline bool regs_within_kernel_stack(struct pt_regs *regs, 287 unsigned long addr) 288 { 289 return ((addr & ~(THREAD_SIZE - 1)) == 290 (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1))); 291 } 292 293 /** 294 * regs_get_kernel_stack_nth() - get Nth entry of the stack 295 * @regs: pt_regs which contains kernel stack pointer. 296 * @n: stack entry number. 297 * 298 * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which 299 * is specified by @regs. If the @n th entry is NOT in the kernel stack, 300 * this returns 0. 301 */ 302 static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, 303 unsigned int n) 304 { 305 unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs); 306 addr += n; 307 if (regs_within_kernel_stack(regs, (unsigned long)addr)) 308 return *addr; 309 else 310 return 0; 311 } 312 313 #endif /* __ASSEMBLY__ */ 314 315 #ifndef __powerpc64__ 316 /* We need PT_SOFTE defined at all time to avoid #ifdefs */ 317 #define PT_SOFTE PT_MQ 318 #else /* __powerpc64__ */ 319 #define PT_FPSCR32 (PT_FPR0 + 2*32 + 1) /* each FP reg occupies 2 32-bit userspace slots */ 320 #define PT_VR0_32 164 /* each Vector reg occupies 4 slots in 32-bit */ 321 #define PT_VSCR_32 (PT_VR0 + 32*4 + 3) 322 #define PT_VRSAVE_32 (PT_VR0 + 33*4) 323 #define PT_VSR0_32 300 /* each VSR reg occupies 4 slots in 32-bit */ 324 #endif /* __powerpc64__ */ 325 #endif /* _ASM_POWERPC_PTRACE_H */ 326